With continuous development of electronics, micro speakers, as important acoustic components in modern consumer electronics, have been rapidly improved in performance. Enhancing the sound performance of the speakers often needs increasing the size of magnetic circuit systems. However, such electronics as mobiles phones and tablet computers have limitations on the sizes of the micro speakers to some extent. Therefore, in order to increase the size of the magnetic circuit system, those skilled in the art usually balance the size increase by thinning a housing.
However, the above-mentioned technical means of thinning the housing may easily cause reduction of the strength of the housing, which results in reduction of the reliability of the speaker. Hence, those skilled in the art further employ a method of directly disposing a part of a washer in the housing by injection molding so as to achieve the objectives of increasing the size of the magnetic circuit system and guaranteeing the strength of the housing. Nevertheless, due to manufacturing tolerance of the size of the washer, it is inevitable that plastic burrs appear at the splicing portion of the washer and the plastic housing during the integral injection molding process. So, it is possible that these burrs extend into a magnetic gap or other structures of a speaker unit to affect the acoustic performance, the assembly process and the structural stability of the speakers.
To sum up, in order to guarantee the acoustic performance of the micro speakers, it is necessary to avoid the influence on the speaker unit from the extending plastic burrs. Therefore, the housing integrated with the washer by injection molding needs to be improved. Or, a new technical scheme may be employed to prevent the plastic housing from burrs.